Method and apparatus employed in the drilling of wells



E. E. GREVE 1,918,096 METHGD AND APPARATUS EMPLOYED IN THE DRILLING 015 WELLS July 11, 1933.

Filed April 23, 1929 Patented July 11, 1933 UNITED STATES PATENT OFFICE EDGAR E. GREVE, OF BELLEVUE, PENNSYLVANIA, ASSIGNOB, BY MESNE AESIGNMEN TS,

TO OIL WELL SUPPLY COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORA- TION OF NEW JERSEY METHOD AND APPARATUS EMPLOYED IN THE DRILLING OF WELLS Application filed April 23,

This invention relates to the art of rotary drilling of wells, and particularly to a method of and apparatus for enabling the drill stem and its associated parts to be introduced or lowered into operative position in a well against pressure and without accidental stoppage being formed in the stem and/oruts associated parts, due to entrance of forelgn matter.

As is well known to those familiar with this art, the drill pipe or stem is made up of a number, of hollow sections, usually coupled together by tool joints. This stem has connected with its lower end a drill collar, and secured to this collar at its lower end ]S a drill bit.

In rotary drilling, a mud-ladened fluid is forced down through the drill stem, dr ll collar, and through openings formed in the drilling bit. Hence, there must be a passage provided from above the floor of the derrick down to and through a portion of the bit.

In lowering the hollow stem, collar and bit into a well, and particularly into a deep well, or into a well in which the bore has deviated from a straight line, it frequently happens that the bit gouges into the wall of the well, causing material to enter through the openings in the bit and pass upwardly therethrough into the drill collar and, 1n some 1nstances, into the hollow drill stem sections, thus plugging the passage in some or all of the parts mentioned. When this happens, it will be understood that this stoppage must be removed before the drilling operation canstart. In some instances, this stoppage will prevent the downward travel of thestem to operative position. In such cases, it 1s necessary to introduce fluid from the top ofthe well into the drill stem to provide the necessary weight to overcome the pressurein the Well. a

The removal of this stoppage, as heretofore practiced, is sought to be accomplished by passing the mud-ladened fluid down the drill stem and forcing the plugged materlal out throughthe bit openings by the action of a pump. This operation, however, always places a very heavy load on the pump and in some instances is not successful in removing 1929. Serial No. 357,470.

the stoppage; and even when it is accomplished, the pump and other operable parts are subjected to severe strains, frequently causing breakage.

It is the prime object of the present invention to provide a new method of and apparatus for introducing the bit to its operative position Without producing this plugging or stoppage in any or all of the parts above mentioned, and at the same time enabling the drill stem and its associated parts to be lowered against the pressure encountered in the well.

In the accompanying drawing, which illustrates several forms of apparatus that may be employed for carrying out my method:

Fig. 1 is a part sectional View and a part elevational view of apparatus constructed in accordance with my invention, and showing a portion of a tool joint, a drill collar, and a drill bit with the holes of the latter plugged;

Fig. 2, a detail sectional view, particularly showing the lower end of a drill collar and the plugged bit;

Fig. 3, an enlarged detail sectional view, particularly showing a valve construction for controlling fluid ports for the admission of fluid to the hollow drill stem;

Fig. 4, a part sectional and a part elevational view, showing a modified construction; and

Fig. 5, a sectional View, showing a still further modified form of apparatus.

Referring to the drawing, and first to the form of Fig. 1, 5 designates a portion of a section entering into the formation of a hollow drill stem of the character employed in,

rotary well drilling apparatus. The portion 5 may represent a portion of tubing or,- pre'ferably, a portion of a tool joint employed in connection with the sections of pipe or tubing. Secured to the part 5.is a drill collar designated generally by 6.

As illustrated and as preferred, collar 6 has enlarged end portions 7 and 8 and an interposed body'portion 9. This collar, as

well as the part 5, has a central bore forming a passage for communication with the bores of the. pipe sections, not shown, constituting the hollow drill stem, thus providing a passage for mud-ladened fluid adapted to be forced down through the drill stem and utilized in rotary drilling, as is usual.

The upper enlarged end portion 7 has its bore enlarged, as at 10 and 11. The bore portion 11 is slightly tapered and threaded to receive the threaded pin-end of member 5'. The lower end portion 8 of the collar is provided with an internally threaded tapering portion at 12, designed to receive the pinend connection of a drill bit.

Operable within the enlarged portion 7 of the collar is a sleeve valve device including the sleeve proper 14 carrying packing elements 15 and internally threaded collars 16 and 17 mounted on the threaded upper end of the sleeve. Movable with the sleeve and held in operative position between the collars 16 and 17 is a packing cup 18, which aids in preventing the passage of fluid downwardly and on the outside of the sleeve 14. Disposed in the enlarged bore portion 10 and between a shoulder 19 and the collar 17 is a spring 20 adapted to urge the valve device to open position.

Formed in the wall of the upper end of the body of the collar, I provide fluid inlet openings or ports 21 designed to admit fluid from a source below the top of the well into the interior of the hollow stem as the drill stem is being lowered to operative drilling position in the well. These ports 21 are controlled by the action of the valve device, as

will be hereinafter described.

22 designates a drill bit that may be of any preferred type employed in rotary drilling. I have shown a fish-tail bit provided with a tapered threaded shouldered connecting joint 23 formed with vertically extending ports or openings 24 to permit the passage of the mud-ladened fluid employed in rotary drilling down and through a portion of the bit.

In the form under consideration, I have shown these ports 24 closed by displaceable plugs 25 entered in said ports. The purpose of closing the openings 24 is to prevent the entrance of material into and through the said openings while the drill stem is being run down the well.

In the, form of Fig. 4 I employ the drill collar 6 having the fluid inlet ports 21 and its associated valve device of the form of Fig. 1, as well as the same type of bit 22, but embody therewith a tool joint 26 and a coupling member 27, said members 26 and 27 being interposed between the lower end of the drill collar and the upper end of the bit. When using this form, it will be unnecessary to employ the displaceable plug members in I the openings of the bit, for the reason that I have provided means in the coupling 27 for preventing the entrance of material to effect a stoppage in the drill stem. In this instance, I provide a valve 28 designed to be closed on its seat 29 during the operation of running the drill stem into the well by a spring 30 acting in conjunction with a nut 31 on the valve stem and a guide 32.

In the form of Fig. 5, which shows a still further modified form, I employ a drill collar 6a having a series of staggered openings in the Wall thereof, in each of which is placed a ball valve device including a cage 33 having ports a and b, a seat 34, and a ball 35 operable to admit fluid to the interior of the collar from a source in the well and below the top of the well, while the drill stem is being lowered and to close to stop the admission of said fluid when the pressure in the interior of the collar is greater than the outside pressure.

In practice, the lower end portion of the hollow drill stem, i. e., the drill collar or the bit, is sealed against the entrance of foreign material during its passage down the well until it reaches the operative drilling position. This temporary sealing may be effected by the employment of means ishown by the drawing or by other suitable means. Duringthe lowering operation, fluid in the form of water, usually, water mixed with mud, from a source below the top of the well is admitted to the drill stem above the sealed portion thereof. This introduced fluid aids in lowering the drill stem, due to the'fact that it imparts additional Weight to the stem, thus acting against the well pressure tending to float the stem. It will also be understood that this introduced fluid will aid the pump when mud-ladened fluid from a source above the top of the well is introduced to the hollow drill stem.

By following the method herein described, one is enabled without putting an objectionable load on the pump to break the tem orary seal by forcing the mud-ladened flui down the stem in the usual manner. In the form of my invention shown in Figs. 1, 3 and 4, the spring 20 holds the sleeve, valve 14 in open position during lowering until the pressure of the mud fluid is sufficient to compress the spring 20 and close the opening or openings 21. Even though the spring 20 be so stiff that the sleeve valve 14 has not quite reached closed position when the drill reaches the bottom of the hole, the sleeve valve will close when the mud fluid is put into circulation down the drill stem. It will be understood that when the pump is put into operation, not only is the pressure in the drill stem increased, but there is also a certain effect on the sleeve valve due to the velocity of the mud fluid down the stem. It will be apparent that, as this heavy fluid is passed down the hollow drill stem, it will cause the valve disposed in the drill collar to move into closed position and remain closed so long as the said fluid under pressure is forced down the stern. It is apparent that if the form of my invention shown in Fig. 5 is employed, the check drill bit.

valves 35 will be closed as soon as the pressure within the drill stem exceeds the pressure outside.

I claim:

1. The method of/ introducing a hollow drill stem and a drill bit having a passage communicating with the interior of the drill stem into operative position in a well which comprises initially and temporarily closing the passage through the drill bit, lowering the stem and bit into operative position in the well, introducing fluid into the interior of the stem from a source below the top of the well during the lowering operation, and increasing the pressure within the hollow drill stem to open the passagethrough the 2. In combination, a hollow drill stem having an opening through the wall thereof, a valve actuated by an excess pressure within the drill stem for stopping said opening, a

drill bit carried by the drill stem, said drill bit being provided with a passage for the discharge of mud fluid, and means for closing the discharge passage in the drill bit.

3. In combination, a hollow drill stem having an opening through the wall thereof, a drill bit carried by the drill stem, said drill bit being provided with a passage for the dischargeof mud fluid, means for closing the opening through the wall of the drill stem when the pressure within the drill stem exceeds the pressure outside, and meansvfor temporarily closing the discharge passage in the drill bit.

4. In combination, a hollow drill stem having an opening through the wall thereof, a valve actuated by an excess pressure within the drill stem for stopping said opening, a drill bit carried by the drill stem, said drill bit being provided with a passage for the discharge of mud fluid, and means for temporarily closing the discharge passage in the drill bit, said means being capable of being expelled from the drill bit by an excess of pressure seeln'ng discharge by way of said discharge passage.

5. In combination, a hollow drill stem including a drill collar having an opening through the wall thereof, a valve actuated by an excess pressure within the drill stem for stopping said opening, a drill bit secured to said collar, said drill bit being provided with a passage for the discharge of mud fluid,

and means for temporarily closing the discharge passage in the drill bit.

6. In combination, a hollow drill stem hav .ing an opening through the wall thereof,

check valve mechanism for closing said passage in the drill stem against discharge of fluid yet permitting fluid to enter, a drill bit carried by said drill stem, said drill bit being provided with a passage for the dis-' charge of mud fluid, and means for temrarily closing the discharge passage in the drill bit.

In testimony whereof I aflix my signature.

EDGAR E. GREVE. 

